ZAGREB, Croatia -- Croatian police have detained nine people suspected of smuggling migrants into the European Union country from neighboring Serbia, a police statement said on Friday.

       The suspects joined forces with unidentified persons in Serbia to organize illegal entry over the Danube River for foreign nationals and financial gain, the statement said. All the detained suspects are Croatian citizens, the statement added.

       The Danube separates Croatia in the east from Serbia. Both countries lie on the so-called Balkan land route used by migrants trying to reach Western Europe.

       Thousands of people from the Middle East, Africa or Asia usually reach Greece or Bulgaria from Turkey, before heading toward North Macedonia, Serbia or Bosnia.

       From Serbia, migrants often rely on people smugglers to cross without authorization into the neighboring EU states of Croatia, Hungary and Romania. They are in danger of facing abuse, closed borders and harassment.